When I build openoffice with NUMOFPROCESSES=4 the system starts to act unresponsive after some time on my Core2 Duo, very similar to a single core system running make -j. However if I set debug.vfscache=0 the system immediately becomes responsive again. After resetting debug.vfscache to 1 the system _remains_ responsive. I'm considering to put debug.vfscache=0 debug.vfscache=1 into my sysctl.conf. Whatever causes this behaviour, I doubt it is intended.